literal := number-literal | string-literal | character-literal | symbol-literal

string-literal := single-quote string-character* single-quote
string-character := normal-character | (single-quote single-quote)
single-quote := "'"
normal-character := character-except-single-quote

character-literal := "$" character
character := normal-character | "'"

symbol-literal := "#" symbol-body
symbol-body := identifier | keyword+ | binary-selector | string

unary-selector := identifier
binary-selector := binary-selector-character+
binary-selector-character := "+" | "/" | "\" |  ...
selector-argument := identifier

identifier := alpha-char (alpha-char | digit-char)*
keyword := identifier ":"



class-definition := #class class-modifier? "{" class-body "}"
class-modifier := "(" (#byte | #character | #word | #pointer)? ")"
class-body := variable-definition* method-definition*
 
variable-definition := (#dcl | #declare) variable-modifier? variable-list "."
variable-modifier := "(" (#class | #classinst)? ")"
variable-list := identifier*

method-definition := (#mth | #method) method-modifier? method-actual-definition
method-modifier := "(" (#class | #instance) ")"
method-actual-definition := method-name "{" method-tempraries? method-primitive? method-statements* "}"

method-name := unary-method-name | binary-method-name | keyword-method-name
unary-method-name := unary-selector
binary-method-name := binary-selector selector-argument
keyword-method-name := (keyword selector-argument)+

method-temporaries := "|" variable-list "|"
method-primitive := "<"  "primitive:" integer ">"
method-statements := method-statement ("." | ("." method-statements))*
method-statement := method-return-statement | method-expression
method-return-statement := "^" method-expression

method-expression := method-assignment-expression | basic-expression
method-assignment-expression := identifier ":=" method-expression
basic-expression := expression-primary (message-expression cascaded-message-expression)?
expression-primary := identifier | literal | block-constructor | ( "(" method-expression ")" )

----------------------------------------------------------

message-expression := (unary-message-expression+ binary-message-expresson* keyword-message-expression?) |
                      (binary-message-expression+ keyword-message-expression?) |
                      keyword-message-expression
cascaded-message-expression := (";" message-expression)*
keyword-message-expression := (keyword keyword-argument)+
keyword-argument := expression-primary unary-selector* binary-message-expression*
binary-message-expression := binary-selector binary-argument
binary-argument := expression-primary unary-selector*

------------------------------------------------------------

#include '....'.

#class Test(Object) 
{
}

#main